Plastic glue: Everything you need to know
You can fix any plastic with the right kind of glue. We can tell help you find the perfect solution for your project.
Plastic is used in countless applications, from toys to spacecraft. Its uniquely flexible and durable composition makes it incredibly useful, but it also creates problems when repairing with glue, as many adhesives can dissolve or fail to properly bond with the plastic. You need to find the right adhesive for the job, and the product must be meant for your specific plastic type.
Many different types of plastic are used in commercial applications, each with its own distinct properties. Knowing these types helps to decide what is the best plastic glue for any job.
The easiest way to identify a plastic type is by its label, commonly a recycling symbol. Plastics marked with a 6 or “PS” are polystyrenes. These are used for simple items like disposable cutlery, plastic bowls, or fashion bags. For these, the best glue is a poly cement such as Loctite Plastic Bonder.
Other types of plastic are used for tougher industrial or construction uses, such as drainpipes. Special plastics are even used for medical applications and bulletproof vests. For gluing these plastics, try Loctite Plastics Bonding System, which creates a powerful bond with just one drop.
Hard, high-density plastics, such as those used to make buckets, crates, or containers, are made from polyethylene and polypropylene. Ordinary white glues, wood glues, or common adhesives won’t react well or form permanent bonds with these plastics. For the strongest glue to use on harder plastics try Loctite Plastics Bonding System, a two-part cyanoacrylate adhesive. It’s water-resistant, sets in seconds with minimal application, and dries clear.
Flexible plastics are commonly used in household items such as shoes or toys. Look for adhesives specially formulated for use with these materials. The best glue to use on flexible plastics is Loctite Vinyl, Fabric & Plastic Flexible Adhesive. It’s a clear liquid adhesive that’s waterproof, dries clear, and creates a flexible bond that won’t break down or yellow from UV/sunlight exposure.
Some fixes need an extra degree of strength. For bonding materials, such as polycarbonate, acrylic, Nylon, Mylar, Delrin, phenolic, aluminum, and stainless steel, the strongest adhesive to use is Loctite Plastic Bonder. Its specialized acrylic formula combines two components to produce a strong, impact-resistant bond that sets in less than half an hour. Once full cure is achieved (in approximately 24 hours), it’s resistant to water, as well as common shop fluids and solvents.
Gluing plastics doesn’t have to be difficult. Here are a few tips to make joining plastic easy.
- Clean your plastic surface. Before gluing, always wash plastic with soap, use a specialized plastic cleaner, or soak the plastic in isopropyl alcohol to clean. Dry thoroughly. Avoid touching the plastic with bare hands to minimize oil residue.
- Sand the surface. To create a rough surface for the glue to bond to, sand the plastic with 120 to 200 grit sandpaper. Steel wool or emery cloth will also work, but remember it only needs to be rubbed briefly. To make your life easier, the Loctite two-part plastic bonding system has an activator that helps roughen the surface.
- Get precise. For precise, detailed plastic glue application, use a small paintbrush or the tip of a needle.
- Mix components if required. Two-part epoxies or adhesives are durable, but they need some preparations. Read your product’s instructions carefully for blend ratios. Mix as directed to activate the adhesive.
- Clamp for a firm seal. Sealing pieces tightly is crucial. Use a clamp, tape, or elastics to hold parts firmly together while glue dries. Curing times can range from a few minutes up to 24 hours, so check your product directions.
- Cleanup and storage. Remove any excess uncured glue or spillage immediately using isopropyl alcohol or denatured alcohol. Mineral spirits can also be used. Seal the bottle tightly and store in a dry location at a temperature below 75°F (24°C).